This invention relates to propellers, and in particular, to a hub assembly for translating rotational movement from a propeller shaft of a marine vehicle to the blades of a propeller.
It is known to propel a marine vehicle utilizing a propeller assembly mounted on a rotatable shaft. The propeller assembly includes propeller blades extending from a central hub. A motor rotates the drive shaft which, in turn, rotates the central hub and the propeller blades. A hub assembly is provided to interconnect the central hub to the drive shaft. As is known, rotation of the propeller blades extending from the central hub propels the marine vehicle through the water.
Typically, the propeller assembly is constructed as a unit wherein the propeller blades, the central hub and the hub assembly are mounted or removed from the drive shaft in unison. Typically, the central hub of the propeller assembly includes an outer cylindrical housing which is welded or otherwise attached to a plurality of propeller blades. The central hub also includes an inner cylindrical housing which is co-axial with the outer cylindrical housing and radially spaced therefrom. The inner housing is supported within the outer housing by a plurality of circumferentially spaced ribs. The propeller assembly further includes a hub assembly disposed within the inner cylindrical housing of the propeller hub assembly. The hub assembly includes a drive member having an inner surface which meshes with splines on the outer surface of the drive shaft and an outer surface. A bushing formed from a rubber or elastomeric material is provided between the inner surface of the inner housing and the outer surface of the drive member. The elastomeric bushing provides shock absorbency between the propeller hub assembly and the drive shaft.
It has been found that slippage may occur between the elastomeric bushing and the inner surface of the inner housing. Once slippage has occurred, the outer surface of the elastomeric bushing becomes more common. Consequently, once slippage has occurred, it becomes necessary to replace the propeller assembly in order to once again realize the power capabilities of the motor of the marine vehicle.
In addition, it is known that the drive shafts driven by the various motors for marine vehicles differ depending upon the manufacture. Consequently, individual propellers must be provided for the drive shafts of each motor brand. Maintaining an inventory of specific propellers for each brand of motor requires significant storage space and may be cost prohibitive.
Therefore, it is a primary object and feature of the present invention to provide a hub assembly for a propeller which discourages slippage between the coupling element and the inner surface of the inner housing.
It is a still further object and feature of the present invention to provide a hub assembly for a propeller which may be easily adapted for mounting propellers on the drive shafts of different manufacturers"" motors.
It is a still further object and feature of the present invention to provide a hub assembly for a propeller which is simple and inexpensive to manufacture.
In accordance with the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a hub structure extending along a longitudinal axis. The hub structure includes an outer surface having a plurality of circumferentially spaced blades projecting therefrom and an inner surface having a longitudinally extending key projecting therefrom. The key is a predetermined distance from the longitudinal axis. The propeller assembly also includes an adaptor having an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a longitudinally extending key extending therealong. The key of the adaptor is also the predetermined distance from the longitudinal axis.
The propeller assembly may also include a tubular bushing about the adaptor. The bushing has a portion disposed between the key of the hub structure and the key of the adaptor. The tubular bushing includes an inner surface engageable with the outer surface of the adaptor and an outer surface engageable with the inner surface of the hub structure. It is contemplated to form the tubular bushing from a resilient material.
In accordance with the further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a hub structure extending along a longitudinal axis. The hub structure includes an outer surface and an inner surface having a longitudinally extending key projecting therefrom. The propeller assembly also includes an adaptor having an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a longitudinally extending key extending therealong. The key of the hub structure and the key of the adaptor lie on a generally circular key path. The key path having a predetermined radius.
A tubular bushing may be positioned about the adaptor. The tubular bushing includes a portion disposed between the key of the hub structure and the key of the adaptor. In addition, the tubular bushing includes an inner surface engageable with the outer surface of the adaptor and an outer surface engageable with the inner surface of the hub structure. It is contemplated that the tubular bushing be formed from a resilient material.
The inner surface of the adaptor may include splines to mesh with the splines on the rotatable propeller shaft of the watercraft. The outer surface of the hub structure includes a plurality of circumferentially spaced blades projecting therefrom.
In accordance with a still further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a hub structure extending along a longitudinal axis. The hub structure includes an outer surface and an inner surface having a plurality of circumferentially spaced, longitudinally extending keys projecting therefrom. The propeller assembly also includes an adaptor having an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a plurality of circumferentially spaced, longitudinally extending keys extending therealong. Each key of the adaptor is disposed between the corresponding pair of keys projecting from the inner surface of the hub structure.
The outer surface of the hub structure includes a plurality of circumferentially spaced blades projecting therefrom. A tubular bushing may be provided about the adaptor. The tubular bushing includes a plurality of bushing portions. Each bushing portion is disposed between a key projecting from the outer surface of the adaptor and a corresponding key projecting from the inner surface of the hub structure. The tubular bushing also includes an inner surface engageable with the outer surface of the adaptor and an outer surface engageable with the inner surface of the hub structure. It is contemplated to form the tubular bushing from a resilient material.